I heard once a long time ago something about how of all the body morphs necessary to go from a chimpanzee-like ancestor to full bipedalism, the changes to our vestibular organs were the most impressive; after all, when walking we are suspended on a sort of small surface, and it’s a wonder we don’t flop around when running.
Is it really such a huge stretch, though? Since chimpanzees sort of brachiate (not like gibbons, but you know), and most other primates are leapers & clingers, or they run along branches…wouldn’t they need pretty heavy duty balance organs too? So they don’t fall and break their necks?
And what about kangaroos? I know they’re kinda tripedalian; do they have better balance than others? And how about birds that walk around on the ground compared to flying ones?
If we really do have stronger vestibular organs than other animals, doesn’t that mean we suffer vertigo easier too? I would imagine so, but mightn’t that give a negative effect when bouncing around in treetops or whatever?
I admit to having trouble Googling on the animal part of this particularly, thus I came here.
I don’t really understand why the fact humans walk upright would mean any change to the vestibular apparatus. That makes no sense to me at all.
Do you have any cite for this?
There was a Discovery Channel show on the evolution of man where they showed a mold of the rings in the inner ear of Australopithecus vs Homo sapiens. The difference was very striking. Homo’s rings were about twice the size.
Look at a table with two legs… now make it stand upright on two legs… which one will require more active balancing on your behalf? I don’t see what you don’t understand?
Wow. I hadn’t remotely expected that much of a difference. I guess even with the tree-dwelling other primates we’d have a significant boost over them then.
True, but the OP question is a very valid one. Birds are also bipedal (and then they fly!) and brachiators and other “athletic” animals also have some pretty serious balance needs.
The program I watched offered this vestibular difference as a partial explanation as to how Homo outcompeted Australopithecus. The gist of it was that Homo having better balance was more suited to run and track prey. It was late, I was tired and posting here at the same time. Don’t ask me much more :o
